Electrical Connector for a Hearing Device

ABSTRACT

This invention relates to an electrical connector for generating an electrical connection between at least a first electric conductor and at least a second electric conductor, e.g. for generating an electrical connection between the lead wires of a connector mounted between the ear side unit and receiver of a hearing device and the receiver, wherein said electrical connection is based on pressure of at least one of said conductors against a pressure-sensitive conductive elastomer fixated between said at least two electric conductors. The present invention further relates to a hearing device comprising an ear side unit, a receiver and an electrical connection between said ear side unit and said receiver, wherein said electrical connection comprises at least an electrical connector as described above. The invention also relates to a method of generating an electric connection between at least a first electrical conductor.

FIELD OF THE INVENTION

The present invention relates to electrical connectors and especiallyelectrical connectors for generating an electrical connection betweenthe lead wires connecting the receiver and ear side unit of a hearingdevice and the receiver.

BACKGROUND OF THE INVENTION

Headsets and hearing devices often comprise an ear side unit placedbehind the ear and a receiver (loudspeaker) placed in or near the earchannel. The ear side unit comprises, in connection with hearingdevices, a number of microphones for detecting sounds and a datahandling and amplifier unit for data handling and amplification of thesound signals recorded by the microphone. The data handled and amplifiedsound signals are hereafter transmitted to the receiver through leadwires drawn from the ear side unit to the receiver, where the soundsignals would be converted into sounds waves inside the ear channel andthereby improving the user's listening skills. The ear side unit couldin connection with headsets instead of microphones for instance comprisea radio receiver for receiving sound signals transmitted as radio waves(FM, AM, Bluetooth, etc.) and thereby enable the user to receive andhear sound signals transmitted as radio signals.

The lead wires connecting the ear side unit and the receiver aretypically drawn through a sound tube. The sound tube and receiver aretypically connected such that both the sound tube and receiver need tobe replaced in case of malfunction or breakdown of the sound tube orreceiver, which is both time-consuming and expensive. The lead wires aretypically brazed to the receiver, and both the sound tube and receiverare therefore replaced in case that the sound tube and lead wires breakas it is very time-consuming to replace only the sound tube. Anotherproblem in this connection is the fact that the ear is different fromperson to person, and therefore the hearing device manufacturers need tosupply different receivers with lead wires of different lengths for eachhearing device such that the audiologists can adjust the hearing deviceto the user. Today, the manufacturers braze the receiver to the leadwires and therefore they need to supply one receiver per differentlength of lead wire. There is further a risk that the receiver might bedamaged when brazing the lead wires to the receiver as heat may beconducted through the electric conductors of the receiver and thusdamage the electrical components or circuit.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to overcome some or all of theabove-mentioned problems.

This is achieved by the invention as defined by the independent claims,and other advantageous embodiments of the invention are defined by thedependent claims. The benefits and advantages of the present inventionare explained and discussed in the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, preferred embodiments of the invention will bedescribed referring to the figures, where

FIGS. 1 a and 1 b illustrate a hearing device according to prior artcomprising a connector connecting the ear side unit and receiver of thehearing device;

FIGS. 2 a and 2 b illustrate an embodiment of a connector connecting theear side unit and receiver of a hearing device, and which comprises anelectric connector according to the present invention.

FIG. 3 illustrates an enlarged view of the assembled electricalconnector according to the present invention.

DESCRIPTION OF EMBODIMENTS

FIGS. 1 a and 1 b illustrate a hearing device as known in the prior art,where FIG. 1 a illustrates how the hearing device (101) is placed on theear (103) and FIG. 1 b illustrates the hearing device without the ear.The hearing device comprises an ear side unit (105) placed behind theear, a receiver (107) placed within the ear channel (109) or could inother embodiments be placed near the ear channel. The ear side unitcomprises a microphone array (111), a battery chamber (113) for powersupplying of the hearing device, a volume control (115) enabling theuser to turn the volume up and down and a processing and amplifying unit(not shown since it is enclosed). The microphones record the sound andconvert the acoustic signals into electric signals, and the processingand amplifying unit would hereafter typically filter and amplify theelectric signals. The processing and amplifying unit could beimplemented as analog units, digital units or a combination of bothanalog and digital units. The ear side unit is through a sound tube(117) connected to the receiver (107) typically integrated into areceiver housing which fits the user's ear channel. The sound tubecomprises a number of lead wires (not shown) drawn through the soundtube, and the lead wires are connected to the processing and amplifyingunit at the ear side unit and to the receiver. The receiver housing andsound tube typically engage with each other and the lead wires couldtherefore be drawn out of the sound tube and into the receiver housingwhere they are brazed to the electrical conductors of the receiver.Thereby the processed and amplified signals could be transmitted fromthe ear side unit behind the ear to the receiver inside the ear channel,where the receiver converts the electric signals into acoustic signals.The sound tube is made of a relatively stiff material and adapted to fitaround the ear (103) and to positioning the ear side unit behind the earand the receiver inside the ear channel as illustrated in FIG. 1. Thereis always a risk that some of the components of the hearing device couldbreak and thus must be repaired or replaced. Both the receiver and thesound tube are typically replaced in case that either the sound tube orreceiver is broken since it is very complicated and time-consuming toreplace only one of these components. The reason for this is the factthat the lead wires need to be brazed of the receiver which is acomplicated process as the size of lead wires and conductors of thereceiver are very small, and further there is a risk that the receivermight be damaged when brazed. The manufacturers therefore find is easierto replace both components rather than replacing the broken component,and there is therefore a large waste of components, especially when onlythe sound tube breaks because then the more expensive receiver is oftendiscarded.

FIGS. 2 a and 2 b (an exploded view) illustrate an embodiment of a isconnector (201) connecting the ear side unit (not shown) and receiver(107) of a hearing device, and which comprises an electric connector(200) according to the present invention.

The receiver is in the illustrated embodiment placed in a receiverhousing (207) that can be positioned in the user's ear channel. Thereceiver housing can have many different shapes and forms depending onthe manufacture specifications. The connector (201) is in thisembodiment constructed as an isolated wire comprising a number oftwisted lacquered conducting wires (202 a, 202 b) onto which an outerisolating jacket (209) has been extruded. Each lacquered conductingwires comprises in one embodiment a number of lacquered magnet wiresthat are twisted together and form a helix. One or more of the magnetwires could be colored and thereby form a tracer for easy identificationof each lacquered conducting wire. The lacquer could for instance bepolyamide. By lacquering the magnet wires individually they can bedisplaced relatively to each other and they therefore form a veryflexible and soft lacquered wire. The twisted lacquered conducting wiresare isolated from each other due to the lacquer. The connector could inanother embodiment alternatively be constructed as a tube made of a softand flexible material, where the lead wires are drawn/pushed through thetube. The ends (202 a, 202 b) of the twisted lacquered conducting wirescan be connected to the receiver (107) and to the ear side unit. In theshown embodiment the soft and flexible connector (201) further comprisesan ear side stiffener (203) formed as a stiff tube that is fastened tothe ear side unit and shaped as a curve such that it fits around theupper part of the ear helix. The connector (201) is therefore drawnthrough the ear side stiffener (203) and enters the ear side unit wherethe lead twisted lacquered wires (202 a, 202 b) are connected to theelectrical means of the ear side unit, e.g. by brazing or by using anelectric connector as described below. In the illustrated embodiment theends of the lead twisted lacquered wires each comprises a conductor shoe(215 a, 215 b) which is brazed to the ends. The ear side stiffener (203)would therefore be able to fixate the ear side unit behind the ear. Theconnector further comprises a receiver side stiffener (205) formed as astiff tube connected to a receiver housing (207) shaped to fit theentrance of the ear channel such that the receiver housing (207) wouldbe maintained in a position inside the ear channel. The receiver housing(207) surrounds the receiver (107), and the twisted lacquered wires (202a, 202 b) enter the receiver housing through the receiver side stiffener(205) and they can thus be connected to the receiver inside the receiverhousing.

The electrical connector (200) according to the present invention iscomprised in the receiver housing and comprises a pair of connectorhousings (211 a, 211 b), a pressure-sensitive conductive elastomercontact (213), an o-ring (217) and a dowel pin (219). The pair ofconnector housings are adapted to secure the receiver side stiffenerwhen welded or clamped together and fixated by e.g. adhesive and/or theo-ring. The o-ring further prevents air, moist and dirt fro entering thereceiver housing. The isolated wire/lead wires would therefore enter theelectrical connector (200) through the receiver side stiffener (205),and the conductor shoes (215 a, 215 b) of the lacquered conducting wires(202 a, 202 b) would be secured adjacent to the pressure-sensitiveconductive elastomer contact (213). The conductor shoes can in anotherembodiment be omitted, and the ends of the lead wires are then securedadjacent to the pressure-sensitive conductive elastomer. The isolatedwire comprises in one embodiment a strength fiber which could be securedto the connector housings (211 a, 211 b) at a securing area (315). Whenassembled the electrical connecter is inserted into the receiver housing(207) and secured by the dowel pin (219), which is inserted in a dowelhole (221) in the receiver housing (207). The pressure-sensitiveconductive elastomer contact would then get in contact with the electricconductors of the receiver and the electrical conductor shoes (215 a,215 b) of the twisted lacquered wires (202 a, 202 b) and becomeelectrically conducting as the dowel pin provides pressure connectorhousings (211 a, 211 b) such that the pressure-sensitive conductiveelastomer is squeezed/pinched between the receiver conductors andconductor shoes. The pressure-sensitive conductive elastomer compoundexhibits high resistance (insulating performance) when it is innon-pressed/squeezed/pinched condition and the resistance of which, asthe compound is pressed/squeezed/pinched, varies according to themagnitude of the pressure. The elastomer therefore become electricallyconducting when put on pressure. The pressure-sensitive conductiveelastomer could for instance be produced as described in U.S. Pat. No.5,175,214 incorporated herein by reference or could e.g. be the Zebra®Carbon, Zebra® Silver, Zebra® Gold elastomers from Fujipoly® or otherpressure-sensitive conductive elastomer provided by Shin-Etsu Polymer.

It is possible to design and build a very small electric connectionwhich could e.g. be used in connection with hearing devices by using apressure-sensitive conductive elastomer when creating an electricconnector as there are less requirements to tolerances when using thepressure-sensitive conductive elastomer compared to when using onlymechanical contacts. The conductors between which an electricalconnection needs to be established simply need to be pressed against thepressure-sensitive conductive elastomer in order to establish electricalconnection there between. In contrast hereto a mechanical connectiontypically comprises a male and female plug that must be designed to fiteach other, and therefore large tolerances to the plugs are requiredwhen creating very small connections.

In connection with hearing devices the electric connector (200) makes itpossible to replace the isolated wire or the receiver very fast andeasy. The dowel pin (219) would in this case be pushed out of the dowelhole (221) and the connector housings could then be separated whereafter the connector shoes (215 a, 215 b) of the isolated wire (201)could easily be removed from the connector housing. The connector shoesof a new isolated wire could then easily be replaced adjacent to theelastomer contact (213), and a new electrical contact between the leadwire and receiver could then be established by assembling the electricconnector again. The receiver could of course also be replaced in asimilar way. Hereby is achieved that the lead wires or receiver could bereplaced without brazing at the receiver and thereby it is preventedthat the receiver is damaged when brazing. Further, the hearing devicemanufacturer only needs to supply one receiver per hearing device as itis now possible to supply a number of lead wires which could easily beconnected with the receiver, with different lengths along with thereceiver. As a consequence, many resources are saved.

FIG. 3 illustrates an enlarged view of the assembled electricalconnector (200) where the receiver housing (207) and one of theconnector housings (211 b) have been removed. The connector housing (211a) comprises a stiffener recess (301) into which the receiver sidestiffener (205) fits, and the receiver side stiffener comprises anannular flange (303) which is secured in a widening in the recess (301).The connector further comprises a number of conductor shoe recesses(305) into which the conductor shoes (215 a) of the lacquered conductinglead wires (202 a) fit. The conductor shoes (215 a) are in theillustrated embodiment embodied as u-shaped shoes formed in anelectrical conducting material, and the ends of the lacquered conductionwires are inserted into the u-shape. The lacquered conduction wirescould be brazed to the conductor shoes in connection with the productionof the isolated wire, or the shoes could be squeezed together around theends of the lacquered wires. The connector housing further comprises anelastomer recess (307) into which the pressure-sensitive conductiveelastomer contact (213) fits and it is placed adjacent to the conductorshoe recesses such that the conductor shoes would be placed adjacent tothe elastomer contact. The elastomer contact is on the other side placedadjacent to the electrical conductors (309 a, 309 b) of the receiver(107).

The receiver is fixated inside the receiver housing and the connectorhousings (211 a, 211 b) would be pushed towards the receiver housing asillustrated by arrow (310) when the dowel pin (219) is inserted into thedowel hole. The result is that the elastomer contact would bepressed/squeezed/pinched between the conductor shoes (215 a, 215 b) ofthe lead wires and the conductors of the receiver (309 a, 309 b) andthereby create an electric connection there between.

The elastomer used in the illustrated embodiment is a Zebra® Silver fromFujipoly which comprises a large number of layers of isolating material(311, illustrated as dark strips), which in contrast to the other partsof the elastomer contact does not become electrical conducting when putunder pressure, separated by layers of pressure-sensitive elastomer(312, illustrated as bright strips) based on silver stings. Theisolating parts would therefore isolate the electric contacts (309 a,309 b) and thus prevent short circuits there between. Alternatively, theelastomer could comprise two conducting sections separated by a singleisolating section, or the electric connector could be constructed suchthat only the parts of the pressure-sensitive conducting elastomer thatare placed just beside the conductors would be squeezed, and the middlesection of the elastomer would therefore not be squeezed and thus not beelectrically conducting.

It is to be understood that the illustrated embodiments only serve asillustrating examples rather than limiting the scope of the claims. Aperson skilled in the art may be therefore able to construct alternativeembodiments within the scope of the claims.

1. An electrical connector for generating an electrical connectionbetween at least a first electric conductor and at least a secondelectric conductor, e.g. for generating an electrical connection betweenthe lead wires of a connector mounted between the ear side unit andreceiver of a hearing device and the receiver, wherein said electricalconnection is based on pressure of at least one of said conductorsagainst a pressure-sensitive conductive elastomer fixated between saidat least two electric conductors.
 2. An electrical connector accordingto claim 1, wherein said electrical connector comprises fixating meansadapted to fixate said pressure-sensitive conductive elastomer andpressing means adapted to press at least one of said conductors againstsaid pressure-sensitive conductive elastomer.
 3. An electrical connectoraccording to claims 1-2, wherein said electrical connector comprises atleast one connector housing fixating said at least first conductor andsaid pressure-sensitive conductive elastomer adjacent to each other. 4.An electrical connector according to claims 2 and 3, wherein saidpressing means being adapted to press said connector housing againstsaid at least second conductor whereby said second conductor beingpressed against said pressure-sensitive conductive elastomer fixated bysaid housing.
 5. An electrical connector according to claims 1-4,wherein said at least first conductor is the conductor of a lead wireconnecting the ear side unit and receiver of a hearing device.
 6. Anelectrical connector according to claims 1-5, wherein said at leastsecond conductor is the conductor of a receiver of a hearing device. 7.An electrical connector according to claim 6, wherein said connectorhousing is adapted to be inserted into a receiver housing comprising thereceiver, and wherein said pressuring means are adapted to press saidconnector housing against said receiver whereby said conductors of saidreceiver are pressed against said pressure-sensitive conductiveelastomer.
 8. A connector to be mounted between the receiver and the earside unit of a hearing device, said connector comprises at least onelead wire for electrically connecting said ear side unit and saidreceiver, wherein said connector further comprises at least oneelectrical connector according to claims 1-7.
 9. A hearing devicecomprising an ear side unit, a receiver and an electrical connectionbetween said ear side unit and said receiver, wherein said electricalconnection comprises at least an electrical connector according toclaims 1-8.
 10. A method of generating an electric connection between atleast a first electrical conductor and at least a second electricalconductor, e.g. for generating an electrical connection between the leadwires of a connector mounted between the ear side unit and receiver of ahearing device and the receiver, wherein said method comprises the stepof: pressing at least one of said conductors towards apressure-sensitive conductive elastomer positioned between said twoelectric conductors.